Hydraulic machine



y 9, 1933. R v. TERRY 11,9(WA66 HYDRAULIC MACHINE Filed April 1, 1932 4Sheets-Sheet 1 May 9., 1933. R. v. TERRY LQWAfifi HYDRAULI C MACHINEFiled April 1, 1952 4 Sheets-Sheet 2 R. v. TERRY HYDRAULIC MACHINE 4Sheets-Sheet 3 May 9, 1933.

Filed April 1, 1932 May 9, 1933. R. v. TERRY 1,907,466

HYDRAULIC MACHINE Filed April 1, 1932 4 Sheets-Sheet 4 INVENTOR- 5065?102mm BY M W; I HIS TTOR EYS Patented May 9, 1933 UNITED STATES PATENTOFFICE ROGER V. TERRY, 0F HILTON VILLAGE, VIRGINIA, ASSIGNOR TO NEWPORTNEWS SHIPBUILDING AND DRY DOCK COMPANY, A CORPORATION OF VIRGINIAHYDRAULIC MACHINE Application filed April 1, 1932. Serial No. 602,534.

This invention relates to hydraulic machines and particularly those ofthe type that may be used for the generation of power hydraulically or,by applying power thereto, may be used to cause a flow of watertherefrom in the desired direction.

My invention relates more particularly to hydraulic power producingmachines known as hydraulic turbines either of low or of high specificspeed.

The principal object of my invention is to provide a hydraulic turbinein which the blades or vanes of the rotor or runner are pivoted and ofvariable angle with reference to a plane of rotation that isat rightangles to the axis of the runner, the changes in the angles of the-vanesbeing accomplished automatically by the flow of thewater past or throughthe runner.

The accomplishment of the above mentionedobject not only enables aturbine to operate at its maximum efficiency for varying loads but alsoallows the blades of the runner to accommodate themselves to changes inthe hydraulic head or pressure of the source of supply of water and alsoto changes due to the angles of the wicket gates and the changes due tovariations in the speed of rotation of the runner itself.

Automatically variable vanes, when used as in my improved runner,obviously eliminate complicated and expensive parts that have heretoforebeen required when changes in the anglesof the vanes of a runner havebeen produced-byadjustment of certain mechanism at or near the upperportion of the turbine shaft. Among the parts that are thus eliminatedare governor pressure systems that can take care of the total capacityof the turbine, elaborate oil supply apparatus having rotating partsrequiring stuffing boxes that require .re'newal from time to time andthat are often the source of oil leaks, as well as necessary pipes,parts and apparatus re-' matic operation at maximum efiiciency, therunner vanes automatically open or are more inclined when starting aturbine, thereby giving a maximum starting torque with the use ofaminimum flow of water.

The vanes also remain closed or at a minimum angle with the plane ofrotation when the unit is being usedas asynchronous condenser, resultingina minimum loss of power when the runner is operating in either wateror an.

Due to the cushioning action of a dashpot (to be described) foreignobjects carried through the runner give much less trouble and greatlylessen the possibility of damage'to therunner.

My improved runner, furthermore, can be readily installed in a turbinedesigned for use with a fixed blade runner. The substitution of myimproved runner for a fixed blade runner does not require changes in theelectric generator or the usual turbine governor.

It is well known in the turbine art that the angle at which water entersa runner varies with the angular position of the wicket gates, and withthe tangential speed of the runner. The angle of flow of thewaterentering the runner with reference to the circular rotation of therunner, increases rela- It has been found from experiment that thecenters of pressure on the various flow line sections of vanes of theshape and angles of flow normally used for turbine runners are locatedat points varying from 25 to 40 per cent. of the corresponding chorddistances from the leading edge to the trailing edge of the vanes.

It will be appreciated that there is a maximum efliciency position ofthe vane for each combination of flow conditions, consisting of thedirection of water flow entering the runner, the velocity of this flow,and the tan-' gential speed of the runner. With the vane at its properangle to resultin maximum efficiency under these particular conditions,

all forces acting on each vane are equivalent .100

to a single force actin through a center' of pressure. This force timesits distance from the vane axis creates a moment tending to rotate thevane about its axis. This moment is balanced by building into the runnerhub a reactive device acting on the vanes through the proper mechanism.The reactive device includes a piston on the two sides of which there isa difference in pressure, the preponderance acting alwaysin the samedirection and tending to oppose or balance the moment created by thewater flowing through the runner. The preponderance in pressure issecured by the application of the pressure of the head water taken fromthe penstock,

to the space at one side or the other of the piston, as the case may be,the other side of the piston being connected to the draft r a model. Inthe light of experimental data I am, of course, quite familiar with theaction which takes place when the inlet flow angle is changed. This miht perhaps be best illustrated by an examp 'e. Assume the runner tobe insteady operation under certain flow conditions, the hydraulic moment onthe vanes being balanced by the reactive 'moment. Nowassume that theangle of flow relative to the runner is increased by increasing thewicket gate angle or by decreasing the speed of the turbine. This isequivalent to increasing the an 1e of attack as generally known in aeroantics. The center of pressure moves down-stream an appreciable amountand the total force onithe vane also increases, thus increasing themoment about I the vane axis. The hydraulic; turning moment is nowgreater than the reactive moment and a certain angular movement of the.vane in the opening directionwill conseipliently take place. As thevane moves in t e opening direction the angle of attack decreases, thecenter of pressure moves upstream on the vanes, the hydraulic momenttending to open the vanes thus decreases until again balanced by thereactive moment The angular movement of the vanes then stops at thisbalanced position,and the turbine operates with the vanes in the newposition until the flow conditions are again changed. The above actiontakes place automatically.

From the above explanation, it will be clear that the center of pressureis not fixed, but varies somewhat with the flow conditions.

It is mall the change in the center of ressure whic together with thechange in orce .on the vanes, causes the vane movement.

Under normal conditions of operation at or near the best efiiciency forthe various flow conditions, the center of pressure moves an appreciableamount, but not a very large amount, when compared with the chorddistance. When starting up a runner from rest the water impingesdirectly on the vane at a comparatively large angle of attack. Underthis condition the center of pressure moves a relatively large distancedown-stream on the vanes, approaching 50 per cent. of their chorddistances as a limit. I find from experiments that this is a desirablefeature, as the vanes will open wide,-giving the required startingtorque with a minimum quantity of water. As the runner picks up speedthe angle of attack decreases, the center of pressure moves up-stream,thereby reducing the hydraulic turning moment in the vanes, and thevanes therefore close until the hydraulic and reactive moments arebalanced.

Similarly, when the'hydro-electric unit is used as a synchronouscondenser, the runner being driven by the generator with the tur-,

bine gates closed, the angle of attack reaches a large negative valuethe center of pressure moves down-stream a large amount; the vane forceacts on the back side of the vanes causing them to close, thus resultingin a minimum amount of power required to drive the runner in eitherwater or air.

It is deemed preferable to arrange the pivots of the vanes so that theiraxes will be slightly upstream from their normal centers of pressure, sothat they will tend to assume a position somewhat in line with the waterflow entering the runner, in a manner similar to the action of aweather-vane. With the vanes thus pivoted, they will automatically tendto follow any changes in the angle of water entering therunner resultingfrom a change in gate opening or from a change in head.

Figure 8 illustrates how the vanes are preferably pivoted with respectto the center of pressure on the vanes, as found by experiment. Thecross hatched portion represents the development of a section through avane along a flow line through the runner. P represents the center ofpressure whose location varies somewhat with different flow conditionsin the runner but which has been found from experiment to be down-streamfrom a point 25 to 40 per cent. of chord K-K. X represents the axis orpivot point of the vane. Y-Y represents a line through the center ofpressure normal to chord K-K. Wi. 1 the vane s freely pivoted as abovedescribed, they will follow an changes of the water flow passing throngthe runner.

For a detailed description of several embodiments of my invention, whichI at present deem preferable, reference may be had to the followingdescription and to the accompanying drawings forming a part thereof, inwhich Fig. 1 is a vertical sectional view of one form of a turbineembodying my invention.

Fig. 2 is an enlarged cross-section, substantially similar to a portionof Fig. 1, showing connection-for water supply.

F ig.. 3 is a horizontal sectional view on the line 3-3 of Fig. 1.

Fig. 4 is a vertical sectional view on the line 44 of Fig. 1. a

Fig. 5 is a vertical sectional view ofa modified form of the turbine.

Fig. 6 is partly a vertical sectional view of a modified form of theturbine.

Fig. 7 is a part vertical sectional view of a turbine installation ofmodified form.

Fig. 8 is a cross sectional view of one of the-runner vanes, indicatingthe relation of the center of Water pressure to the longitudinal axis ofits pivot.

In these figures, the same numerals refer to similar parts. Referringpariicularly to Figs. l-4, inclusive, 1 is the scroll casing, 12 thewicket gates which are adjusted by the turbine governor in the customarymanner, 3 the throat ring, 4 the draft tube, 5 lllP crown plate, (3 themain bearing, and (5' the main bearing housing. The above parts are ofstandard design well known to the turbine art.

The numeral 7 represents the runner vanes which are pivoted as at 7 inrunner hub 8. 9 and 10 are roller bearings carrying the pivots 7 of vane7. Roller bearings 11 eliminate friction due to the centrifugal forcesof the vanes set up by the rotation of the runner. Gear sector 12 iskeyed to the vane stem within suitable recesses forming greasecontainers, and engages teeth on racks l3 bolted to piston 14 (Fig. 4).Any desired number of runner vanes may be used. The piston 14 serves asa common connecting means for all of the vanes. Since all of the vanesare connected together, they Will move together. The upper part ofrunner hub 8 is bored out to receive piston 14. The depth of the boremay be made just suflicient to give the vanes the proper angular travel.The bottom of the bore and the runner cover 15 will then serve as stopsto limit the angular travel of the vanes in either direction. It will beevident that adjustable means to limit the stroke of the dashpot plunger14 may be used if desired. Obviously the shaft 16 is a continuation ofthe shaft from an electric generator or other power transmitting device.The runner shaft is provided with a central bore or passage 17 andradial passages 19. These passages supply water under pressure to thespace above the piston 14. The shaft is also provided with radialopenings 33 for supplyingoil or grease to the runner hub.

Packings 18, or rubber or other suitable material, are provided for thepurpose of preventing water from entering the hub, and

to prevent the loss of oil or grease around the.

vane stems.

The bottom of the runner hub is provided with a cap 20 that may be heldin place by to work up and down whenthe vanes move angularly on theiraxes. As shown in Fig. 5, the racks may be provided with radial passages24 and vertical passages 25 which form additional means for draining thebottom side of the dashpot piston to the draft tube. Referring now toFig. 6:

Water under pressure is supplied to the space above the top of piston 14from the Water within the scroll casing 1 through coarse strainer 26,piping 27, valve 28, fine strainer 29, lantern ring 31 in stuffing box30, then through holes 17' and 19in the shaft previously mentioned.

If desired, a centrifugal pump 35, Fig. 7, may be used as an auxiliarymeans of water supply interchangeable with 'or in addition to the supplyfrom the scroll casing. The

pump preferably takes its suction from the tail water or draft tube, sothat when the runner is rotating at constant speed the difference inpressure on the, two sides of the piston 14 will be substantiallyconstant although the hydraulic head acting on the turbine may vary by asubstantial amount.

In Fig. 5, water under pressure is admitted to the space above the topof piston 14 through holes 36in runner cover 15.

The runner hub is packed with grease when the runner is assembled andthereafter oil or grease is supplied to the central chamber in therunner hub through the radial holes 33 in shaft 16 and pipe 34 as inFig. 1, or through the pipe 32, holes 33 and pipe 34 as in Figs. 5 and6, whence it passes through the recesses or openings containing theroller bearings,-into the chambers containing the racks 13.

It will be noted that racks 13 pass through the grease containers orspaces as they slide up and down when the vanes turn angularly on theiraxes. This keeps their sliding contacts lubricated. At the same time thevolume of chamber forming the grease space remains substantiallyconstant an'd there is no tendency to force grease out of or to suckwater into the grease chamber.

It will be noted that no connection is provided between the runner vanesand any outside source. of power for turning or oscillating them. Theangular movement of the vanes is entirely automatic and determined bythe action of the water flowing past them,

specific speed with a large number of vanes and to certain forms ofcentrifugal pump vanes or similarly constructed fluid pressure machines.

- What I claim and ters Patent is:

1. In an hydraulic machine having a runner provided with pivoted vanes,the improvement which comprises, providingwithin said runner areactivedevice consisting of a cylinder, a conduit connecting the same with thehead water passage, a piston in said cylinder connected with said vanes,said 'pis-- ton being continuously acted upon by a preponderatingdiflerence in pressure in proportion to the hydraulic head acting on themachine, said diflerence in pressure being always in the same directionand tending to balance the moment caused by the fluid flowing past thevanes to maintain the latter at the desired angle.

2. In an hydraulic machine having a runner provided with vanes which arepivoted so that their axes are upstream from their effective centers ofpressure and so that the fluid. flowing past the vanes will tend to makethem assume a steeper angle relative to their plane desire to protect byLet- .of rotation, a reactive device consisting of a cylinder, a conduitconnecting the same; with i the head water passage, a piston in'saidcylinder connected with said vanes, said piston being continuously actedupon bya preponderating difference in pressure in proportion to thehydraulic head acting on the machine, said difference in pressure beingalways in the same direction and tendin to balance the moment caused bythe fluid owing past the vanes.

fluid pressure produced by said head water, and adapted to bala nce themoment tending to turn said vanes.

4. In an hydraulic machine of the governor operated wicket gate typehaving a runner provided with pivoted vanes, the improve- I mentcomprising, a reactive device connected with said vanes, said reactivedevice including a piston located in a chamber connected with the headwater which operates the ma- -provement which comprises, providing achamber connected with the head water acting upon said machine, a pistontherein connected with said vanes, said piston being acted upon, in onedirection only, by a preponderance of fluid pressure produced by saidhead water whereby the vanes are caused automatically to assume theproper angles for maximum efliciency in accordance with the requiredspeeds of rotation and the angles and rates of Water flow.

6. In an hydraulic machine having a runner provided with. pivoted vanes,a piston connected therewith, and a conduit connected with 'the cylinderwithin which said piston is located and adjacent one side of said pistonand leading from the supply passage and a discharge conduit connectedwith the discharge passage of said turbine and with said cylinderadjacent the other side of said piston so that said piston is acted uponby a preponderance of fluid pressure determined by the relative pressurein the water supply and discharge passages of the machine, respectively.

7. In an hydraulic machine having a runner provided with pivoted, vanes,a piston located in a chamber therein and connected with the turbinesupply passage whereby same direction by a preponderance of fluidpressure, and a conduit extending from said supply passage to the runnercasing for supplying said pressure on said piston.

8. In an hydraulic machine having a runner provided with pivoted vanes,connections between the pivots of said vanesto cause them to movesimultaneously about the axes of their respective pivots, a reactivedevice including a piston having one side adapted to be acted upon byhydraulic pressure applied continuously and in the same direction, a

said piston 1s acted upon always and 1n the conduit connecting thesupply passage of said turbine with the cylinder containing said pistonwhereby said vanes are caused automatically to assume the proper anglesfor maximum efliciency of operation relative to the required speeds ofrotation and the-angles and rates of water flow and dependent upon thepressure supplied by said external source thereof.

9. In an hydraulic turbine having wicket gates for the regulation ofwater flow and a runner having pivoted vanes thereon, the improvementwhich A comprises, providing Within said runner, a reactive deviceactuated by a preponderance of hydraulic pressure applied continuouslyand in the same direction, said reactive device including a piston, achamber enclosing said piston, fluid material in said chamber and supplyanddischarge conduits connected with said chamber and. with the mainsupply and discharge passages for said turbine, said piston alsoconstituting a dashpot plunger, whereby said vanes are caused)rogressi'vely and automatically to assume t e proper angles and bemaintained uniformly at such angles, for maximum cfiiciency inaccordance with the angles of Water flow produced by said gates and therates of Water flow produced by the differences inhydraulic head actingthrough said conduits.

Signed this 18th day of March, 1932.

ROGER v. TERRY.

